The rally came after robust overnight gains on Wall Street, and followed a week of extremely low volatility in mainland stocks.

"Volatility had been very low recently because investors dared not make big bets ahead of the Fed rate decision, for fear of nasty surprises," said Wu Kan, head of equity trading at investment firm Shanshan Finance.

"Now, the uncertainty has been removed."

The blue-chip CSI300 index rose 0.7 per cent, to 3,291.12, while the Shanghai Composite Index gained 0.5 per cent to 3,042.31 points.